Socioeconomic disparities in influenza vaccination uptake: impact of the COVID-19 pandemic in South Korea

BackgroundThis study aimed to investigate the sociodemographic and behavioral factors related to increased influenza vaccination uptake during the COVID-19 pandemic in South Korea, particularly among adults not eligible for free vaccination.MethodsAnalyzing data from 78,815 participants in the Korea National Health and Nutrition Examination Survey (2010-2021), we assessed trends in influenza vaccination coverage. Various sociodemographic factors, behavioral aspects, and psychological stress levels were assessed using multivariable logistic regression to evaluate the difference in vaccination response during pre-/post-COVID-19 periods.ResultsLowest income quartile households exhibited decreased influenza vaccination uptake during the pandemic (adjusted odds ratio 0.67, p = 0.011), whereas higher income quartiles exhibited increased uptake. In the lowest income households, unemployed status of household was additionally associated with decreased influenza vaccine uptake (adjusted odds ratio 0.50, p = 0.003).ConclusionsThis study identified income-based disparities in the responsive increase of influenza vaccination during the COVID-19 pandemic. Lower-income households exhibited a disproportionate reduction in influenza vaccine uptake, emphasizing the need for targeted support systems and expanded free vaccination for prioritized groups to address these disparities.